/* R600+ */
 #define R600_RING_TYPE_UVD_INDEX       5
 
+/* number of hw syncs before falling back on blocking */
+#define RADEON_NUM_SYNCS                       4
+
 /* hardcode those limit for now */
 #define RADEON_VA_IB_OFFSET                    (1 << 20)
 #define RADEON_VA_RESERVED_SIZE                        (8 << 20)
 /*
  * Semaphores.
  */
-/* everything here is constant */
 struct radeon_semaphore {
        struct radeon_sa_bo             *sa_bo;
        signed                          waiters;
 
        }
 
        /* 64 dwords should be enough for fence too */
-       r = radeon_ring_lock(rdev, ring, 64 + RADEON_NUM_RINGS * 8);
+       r = radeon_ring_lock(rdev, ring, 64 + RADEON_NUM_SYNCS * 8);
        if (r) {
                dev_err(rdev->dev, "scheduling IB failed (%d).\n", r);
                return r;
 
 int radeon_semaphore_create(struct radeon_device *rdev,
                            struct radeon_semaphore **semaphore)
 {
+       uint32_t *cpu_addr;
        int i, r;
 
        *semaphore = kmalloc(sizeof(struct radeon_semaphore), GFP_KERNEL);
        if (*semaphore == NULL) {
                return -ENOMEM;
        }
-       r = radeon_sa_bo_new(rdev, &rdev->ring_tmp_bo,
-                            &(*semaphore)->sa_bo, 8, 8, true);
+       r = radeon_sa_bo_new(rdev, &rdev->ring_tmp_bo, &(*semaphore)->sa_bo,
+                            8 * RADEON_NUM_SYNCS, 8, true);
        if (r) {
                kfree(*semaphore);
                *semaphore = NULL;
        }
        (*semaphore)->waiters = 0;
        (*semaphore)->gpu_addr = radeon_sa_bo_gpu_addr((*semaphore)->sa_bo);
-       *((uint64_t*)radeon_sa_bo_cpu_addr((*semaphore)->sa_bo)) = 0;
+
+       cpu_addr = radeon_sa_bo_cpu_addr((*semaphore)->sa_bo);
+       for (i = 0; i < RADEON_NUM_SYNCS; ++i)
+               cpu_addr[i] = 0;
 
        for (i = 0; i < RADEON_NUM_RINGS; ++i)
                (*semaphore)->sync_to[i] = NULL;
                                struct radeon_semaphore *semaphore,
                                int ring)
 {
+       unsigned count = 0;
        int i, r;
 
         for (i = 0; i < RADEON_NUM_RINGS; ++i) {
                        return -EINVAL;
                }
 
+               if (++count > RADEON_NUM_SYNCS) {
+                       /* not enough room, wait manually */
+                       radeon_fence_wait_locked(fence);
+                       continue;
+               }
+
                /* allocate enough space for sync command */
                r = radeon_ring_alloc(rdev, &rdev->ring[i], 16);
                if (r) {
 
                radeon_ring_commit(rdev, &rdev->ring[i]);
                radeon_fence_note_sync(fence, ring);
+
+               semaphore->gpu_addr += 8;
        }
 
        return 0;